Rotary printer for applying a pattern to a flocked sheet

ABSTRACT

A colored pattern is applied exclusively to the raised nap of a flocked sheet by feeding the sheet over a drum roll spaced from one or more engraved rolls. Takeup and letoff units maintain the sheet in a highly tensioned condition on the drum, yet the units are balanced so that they impart no net motion to the sheet. The drum roll is then rotated independently of the units to advance the sheet under substantially constant tension at all speeds from very slow to very fast. The pattern to be applied to the nap is in the form of dye-filled recesses etched into the surfaces of the engraved rolls. The drum roll is critically spaced from the engraved rolls so that the nap fibers in register with these recesses extend into them and are thereby immersed in the dye contained therein. Substantially no pressure is applied to these fibers to be colored so that they are uniformly colored by a combined dipping and wicking action at all sheet speeds.

United States Patent Inventors John H. Johnston;

John H. Johnston, Jr., Somerset, Mass.

Appl. No. 700,243 Filed Jan. 24, 1968 Patented Mar. 9, 1971 Assignee Dabit Inc.

Fall River, Mass.

ROTARY PRINTER FOR APPLYING A PATTERN TO A FLOCKED SHEET 11 Claims, 5 Drawing Figs.

U.S. Cl.

Int. Cl Field of Search 2, 153,178,181,l82,170,184,185,139,140,145,

References Cited UNITED STATES PATENTS 2,324,631 7/1943 May -1:

2,946,280 7/1960 Disch 101/178 2,980,015 4/1961 Zentner et a1. 101/170 3,131,631 5/1964 Haskin,Jr 101/152 FOREIGN PATENTS 900,223 11/1953 Germany 101/178 Primary Examiner-Robert E. Pulfrey Assistant ExaminerJ. Reed Fisher Attorney-Cesari and McKenna ABSTRACT: A colored pattern is applied exclusively to the raised nap of a flocked sheet by feeding the sheet over a drum roll spaced from one or more engraved rolls. Takeup andletoff units maintain the sheet in a highly tensioned condition on the drum, yet the units are balanced so that they impart no net motion to the sheet. The drum roll is then rotated independently of the units to advance the sheet under substantially constant tension at all speeds from very slow to very fast. The pattern to be applied to the nap is in the form of dye-filled recesses etched into the surfaces of the engraved rolls. The drum roll is critically spaced from the engraved rolls so that the nap fibers in register with these recesses extend into them and are thereby immersed in the dye contained therein. Substantially no pressure is applied to these fibers to be colored so that they are uniformly colored by a combined dipping and wicking action at all sheet speeds.

Patented March 9, 1971 2 SheetsSheet l INVENTORS. JOHNSTON JOHNSTON, JR

ATTORNEYS Patented March 9, 1971 3,568,594

2 Sheets-Sheet 2 IN VEN'IY )RS. JOHN H. JOHNSTON BY JOHN H. JOHNSTON.JR.

A I IORNE ROTARY l lillll lTElit FOR AlPilLYH lG A PATTERN TO A FLOQKED SHEET BACKGROUND OF THE INVENTION 1 Field of the Invention This invention relates to method and means for applying a pattern to a flocked sheet. It relates more particularly to a technique for forming multiple-color designs on the raised nap formed by a body of fibers adhering to a backing sheet.

.Flocked sheets are made by a variety of different processes. in one of the more conventional of these, an adhesive pattern is first printed on the sheet. Then flock is sprinkled onto the sheet and it adheres only to those portions coated with the adhesive. After the adhesive sets, the excess flock is removed from the sheet, leaving a raised pattern of fibers on the surface thereof.

There are also various well-known techniques for coloring raised or embossed surfaces. This is done, for example, in the wallpaper industry where dye is applied to a raised design pressed into the paper. The usual procedure for doing this is to pull the paper into the nip between a solid copper print roll and a resilient drum roll. Printing dye is applied to the surface of the print roll. As the paper passes through the nip, the print roll engages the raised portions thereof under pressure and transfers printing dye to the entirety of these portions.

A distinct pattern or design can be printed on the raised portions of the paper in much the same way. For this, the desired pattern is applied to the print roll in the form of raised bosses on the surface thereof. As .the material is pulled through the nip, the inked bosses engage the paper under pressure and transfer the pattern to the raised portions thereof much like a rubber stamp.

2. Description of Prior Art It has been proposed to use the same technique to print a design on the raised nap of a flocked sheet. This has not proved feasible, however, because the sheet supporting the flock, i.e. the backing, is usually a fairly fragile material such as marquisette. Consequently, it is very difficult to control during the printing operation. More particularly, the sheet stretches, creeps and warps as it proceeds through the printing machine with the result that the design being printed on its flock body is frequently blurred. Moreover, the various colors in multiple-color designs are often out of register.

in addition, when these prior printers apply the dye to a flocked sheet under pressure, they are not able to maintain uniform printing pressure over all part of the sheet. Consequently, the printed design often has nonuniform tone and intensity. in extreme cases, skips and gaps appear in the pattern and dye is printed onto the backing sheet itself.

The above difficulties stem in part from the fact that the forces exerted by the resilient drum roll urging the sheet toward the embossings on the print roll are not completely uniform over the entire surface of the drum roll. Also, the rolls themselves have inherent small bows and eccentricities. Moreover, the total nap area in the nip between the rolls varies continuously as the sheet advances. This not only affects the printing pressure, but also may alter the tensioning of the sheet as it passes through the printer and contribute to the design blurring mentioned above.

A further problem arises because in practice the flocked sheet to be printed is often not uniformly tight across its full width. That is, the sheet is tight at its selvedges, but relatively loose in the middle. This situation should be corrected prior to printing to avoid blurring and out-of-register designs by tensioning the sheet.

However, prior printers cannot tension the sheet enough to avoid this objection. This is because they rely on the print and drum rolls to pull the sheet from a controlled feed. Thus, they are unable to pull on the sheet enough to remove the sag without at the same time causing the sheet to stretch or slip somewhat on the drum roll. Such stretching and slippage also spoils the printed design for the reasons noted above.

As a practical matter, in order to obtain an acceptable product, the industry resorts to very elaborate printing techniques. in a typical one of these, the sheet is temporarily adhered to a moving belt during the printing operation to prevent it from stretching and to maintain it under constant tension. While this technique minimizes blurring, it does nothing to solve the aforementioned difficulties caused by variations in printing pressure. ln another such process, prior to flocking it, the backing sheet is chemically treated to make it nonreceptive to the printing dye. This prevents printing on the backing sheet, but does nothing to reduce the incidence of blurring and skips in the printed pattern. Moreover, both of these prior processes are quite complicated and costly.

SUMMARY OF THE INVENTION It is an object of this invention to provide an improved method of applying a pattern in one or more colors to the raised nap of a flocked sheet.

Another object of this invention is to provide a method of applying a sharp and distinct pattern of uniform tone and intensity to the flock body of a limp and fragile flocked fabric.

Still another object of the invention is to provide a method of applying a design comprising several colors in register to the raised nap of a flocked sheet.

Another object of'this invention is to provide improved apparatus for applying a pattern in several colors in register to a body of fibers.

Still another object of the invention is to provide apparatus for accurately applying a distinct design to the raised nap of a flocked sheet.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

' The invention accordingly comprises the several steps and the relation of one or more such steps with respect to each of the others, and the apparatus embodying the features of construction, combination of elements and arrangement of parts which are adapted to effect such steps all as exemplified in the detailed disclosure hereinafter set forth and the scope of the invention will be indicated in the claims.

In general, a sheet of thin backing material is first flock printed to form a raised body of flock fibers arranged in a design on the sheet. The sheet is then fed as needed to the next section of the apparatus which applies a pattern in one or more colors only to the nap formed by the raised body of flock fibers. This step is accomplished by tensioning the flocked sheet between balanced takeup and letoff units which impart no motion to the sheet. The sheet is moved under constant tension at any speed from very slow to very fast by a special rotatable drum roll around which it is engaged. The drum roll rotates independently of the takeup and letoff units. Also, the drum roll is hollow and perforated. A negative pressure is maintained in the roll so that the sheet tends to cling to the roll to minimize slippage between the two.

One or more special rotatable engraved rolls (depending on the number of colors in the printed design being applied to the raised nap) are clustered radially out from the drum roll and operate in synchronism therewith. Each engraved roll carries one of the color patterns to be applied to the nap. Each pattern is in the form of recesses etched into the surface of the engraved roll and loaded with dye in contradistinction to the raised stamplike embossings found on conventional flock printing and tipping rolls. Also, the dye itself is a special high viscosity water emulsion that will be described in more detail later.

The spacing between the drum roll and the engraved rolls is critical for proper application of dye to the nap. Accordingly, we employ a novel technique for carefully controlling this spacing. More particularly, we eschew the conventional'adjustable roll supports and suspend the drum roll from a pair of relatively large, sturdy, but flexible and resilient bars. These bars can be controlably flexed to very gradually ease the drum roll toward the engraved rolls. Our adjustable roll support has substantially no play or reaction which might tend to alter the selected space setting.

The spacing between the drum roll and the engraved rolls is carefully controlled so that the flock fibers opposite those recesses in the engraved rolls situated directly opposite the drum roll are free to extend appreciably into the recesses and take on dye. The flock coloring is enhanced by a controlled wicking action. The other fibers not opposite such recesses and gently deflected by the engraved rolls. It should be noted that as the fabric feeds between the spaced rolls, substantially no pressure is applied to those flock fibers which are to be colored, in contrast to the situation that prevails in prior comparable apparatus.

Throughout this application we will use the terms color and coloring to denominate and describe the aforementioned application of dye to flock by a combined dipping and wicking action under substantially no pressure to distinguish our technique from conventional tipping and printing processes by which dye is pressed or stamped under pressure onto the recipient surface.

All of the engraved rolls are geared directly to the drum roll and rotate in unison therewith so that their surface speeds are the same as the speed of the sheet through the apparatus. Following the above-described coloring operation, the flocked sheet bearing the pattern is subjected to a dry heat and stored on a roll.

The present apparatus thus colors on the pile body a sharp and distinct pattern of uniform color tone and intensity which sits up on the pile body. Furthermore, it minimizes the creation of gaps in the pattern and inadvertant application of dye to the sheet itself.

When a multicolored pattern is being colored on the raised nap, the sheet proceeds from one engraved roll to the next with each roll applying one color portion of the overall pattern to the nap. Since little pressure is applied to the sheet during the coloring operation, any changes in pressure due to varying areas of flock being engaged by the engraved rolls at different times are negligible. For the same reason, the forces tending to cause displacement of the sheet on the drum roll as it proceeds from one engraved roll to the next are likewise small and, in any event, they are offset by the aforementioned nonslip engagement between the sheet and the surface of the drum roll. Consequently, the different color portions of the pattern which are colored successively on the nap are all distinct and in register.

DESCRIPTION OF THE DRAWINGS For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view ofa flocked sheet having a color pattern colored on its raised nap in accordance with this invention;

FIG. 2 is a schematic representation illustrating apparatus for practicing this invention;

FIG. 3 is an enlarged fragmentary perspective view showing in greater detail certain elements of the FIG. 2 apparatus;

FIG. 4 is a fragmentary sectional view on a still larger scale ofa portion of FIG. 3; and

FIG. 5 is a fragmentary side view of the FIG. 2 apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, FIG. 1 shows a sheet made of any natural or synthetic fiber. In the present example, sheet 10 is a thin marquisette fabric. A flower design comprising a pile body indicated at 12 composed of flock fibers 14 is applied to the sheet in a manner to be described, thereby forming a raised nap 14a thereon. The flock may be composed of any suitable material, such as rayon, for example. In certain cases, as in the present example, the underside of sheet 10 may also carry a less pronounced nap 14b directly opposite nap 14a.

A color pattern illustrated here as three interspersed sets of red, green and blue polka dots 16a, 16b and 16c respectively is colored on nap 14a in a manner also to be described. By virtue of its novel application to the flocked sheet to be described presently, each portion of the pattern is characterized by its sharpness and distinctness and uniformity of color tone and intensity. Moreover, the different sets of dots 16a, 16b and are in register, being uniformly spaced relative to one another.

With reference to FIG. 2, the application of the naps 14a and 14b to sheet 10 will be described first. The sheet 10 is served from a roll supply 17 around an idler roll 18 into an adhesive applicator indicated generally at 19. Applicator 19 comprises a container 20 for a liquid adhesive 22. A rotatable feed roll 24 is immersed in adhesive 22 and arranged to transfer the adhesive to an embossed adhesive applicator roll 26. The configuration of the raised bosses 26a on roll 26 corresponds to the design of pile body 12 (FIG. 1). Sheet 10 advances into the nip between roll 26 and a resilient roll 28 and the adhesive 22 is thereby transferred by the bosses 26a to the appropriate areas of sheet 10. In the present example, adhesive 22 also penetrates relatively deeply into, and even through, the sheet by virtue of the meshlike makeup thereof.

Then sheet 10 advances to a flocking station 29 illustrated here by a hopper 30 which sprinkles flock 14 onto sheet 10 as it passes below the hopper. The flock adheres to those areas of the sheet coated with the adhesive 22 as aforesaid. Also, a relatively small amount of flock finds its way to the underside of sheet 10 and adheres to those areas of sheet 10 where adhesive has penetrated.

From the flocking station 29, sheet 10 advances to a drying oven 32 which cures the adhesive, and then it passes to a flock removing station 34 consisting of a chamber 36 through which air is rapidly circulated. The air blows excess flock from the sheet, leaving flock fibers 14 only on those areas thereof to which adhesive was applied as described above. Then the flocked sheet passes through conventional driven feed rolls (not shown) until it is ready for the coloring operation to be described presently. At this point in the process, the sheet looks substantially like FIG. 1 without the colored polka dots 16a, 16b and 160.

Referring to the lower portion of FIG. 2, a coloring unit which prints the different color dots I6a-16c (FIG. I) on the raised nap 14a is indicated generally at 38. The sheet 10, flocked as aforesaid, is served to unit 38 by way of a constant tension letoff unit 40, idler rolls 41 and 42 and a spreader roll 43. From unit 38, the sheet proceeds directly through a dryer 44 and thence to a constant tension takeup unit 45, which is preferably of the dual turret type for maximum efficiency.

Coloring unit 38 comprises a relatively large diameter cylindrical drum roll 47 which is rotated independently of takeup and letoff units 45 and 40. Units 45 and 40 are adjusted to maintain the portion of sheet 10 on drum roll 47 under considerable lengthwise tension. This eliminates any sag problem due to tight selvedges and minimizes the effects of other variations in the sheet material. At the same time, however, units 45 and 40 are balanced so that they do not impart any movement to sheet 10. In other words, the relatively large pulling force exerted by unit 45 is exactly offset by an equally large retarding force due to unit 40. Sheet 10 is advanced through unit 38 solely by drum roll 47 as will be described in detail later.

The spreader roll 43 (or spreader bar) compensates for any reduction in sheet 10 width due to its aforesaid tensioning between units 45 and 40. That is, roll 43 eliminates any creases and restores sheet 10 to its full width just before the sheet engages around drum roll 47. Once the sheet is on roll 47, it can no longer shift or shrink for reasons to be described shortly.

In a working embodiment of the invention, roll 47 is approximately 5 feet long and 28 inches in diameter. Also, to minimize weight, roll 47 is hollow and made of aluminum. A pair of journals in the form of short pipes 48 are butt-welded to the opposite ends of rolls 47 and one or both pipes communicate with the interior of the roll. Preferably, roll 47 is turned down after its journals are attached to assure that the surface of roll 47 is exactly concentric with the journals. Pipes 4% are journaled in a pair of journal boxes 49. Each box 49 is, in turn, secured near one end of a sturdy, fairly rigid, but somewhat flexible and resilient bar 50, the other end of which is mounted by way of a spacer 51 on a base 52. Bars 54 are sufficiently sturdy and rigid to firmly support the relatively lightweight aluminum drum roll 47 without sagging. An adjusting screw 53 is threadedly received through base 52 with its pointed end engaging under the free end of each bar 50. By turning screws 53 one way or the other, the bars 56 can be deflected upwardly to move roll 47, as will be described in more detail later.

As best seen in FIGS. 3 and 4, rolls 41l43 are arranged so that sheet It) engages around substantially three-fourths of the roll 47 surface to ensure maximum contact between the sheet and roll 47. Drum roll 47 has a multiplicity of passages 54 extending from its interior to its outer surface 47a. Typically, passages 54 are about one-eighth inch in diameter and are spaced about one-half inch apart on roll 47. A suction is main tained at these passages by producing a negative pressure inside roll 47. Referring to FIG. 5, this is accomplished by connecting one or both pipes 48 by way of a rotary coupling 55 to a source of negative pressure shown here as a hose 56 connected to a conventional vacuum pump (not shown).

The pressure at passages 54 is selected so that the particular sheet 16 being handled tends to hug and cling to roll 47 in its passage through unit 36. This, in turn, minimizes slippage between sheet and roll 47 and also minimizes sheet 10 shift, spread and skew. It will be appreciated that a greater negative pressure should be maintained when handling a meshlike sheet it) as opposed to a tight woven fabric sheet. Thus, for very loose fabrics, a vacuum connection may have to be made at both pipes 48. Also, for maximum utilization of the existing negative pressure head, a baffle plate 57 (FIG. 2) is preferably spaced closely from the portion of roll 47 not engaged by sheet it) to block the openings 54 that are not being utilized during rotation of roll 47. Also, the surface 47a of drum roll 47 is hard and also it may be textured, i.e. roughened. Thus, it cooperates with the underside of sheet 10 to further reduce relative movement between sheet it) and roll 47.

Three similar, rotatable, cylindrical engraved rolls 58, 59 and 66 are grouped opposite roll 47 approximately the same distance therefrom. Rolls 58, 59 and 60 are equal in length to roll 47, but are preferably smaller in diameter. in the aforementioned embodiment of the invention, these rolls are approximately 5 feet long and 14 inches in diameter. Also, in contrast to conventional print rolls which are made of copper, rolls 54, 59 and 60 are made of steel for increased strength and rigidity.

Rolls 58, 59 and 66 are supported for rotation conventionally by shafts 61, 62 and 63 respectively. After the shafts are attached to their respective rolls, the rolls are turned down to eliminate any eccentricities in the rolls as is done with drum roll 47. The spacing between the three engraved rolls and drum roll 47 is quite critical and will be dealt with presently in greater detail. Each of rolls 55, 59 and 66 is geared directly to drum roll 47 in a conventional way sothat when they rotate, their surface speeds are the same. Together with the vacuumtype drum roll and the textured treatment of its surface 74a, this essentially eliminates slippage between sheet 16 and the surfaces of the various rolls.

This aforementioned technique for supporting roll 47 permits extremely accurate control over the spacing between roll 47 and the three engraved rolls. It does away with the usual sliding fixtures, gears and the like used to adjust conventional rolls. Consequently, it eliminates the lost motion errors occasioned by play between these relatively moving parts. The present construction allows virtually no play between bars 50 and screws 53 or between the screws and base 52 because the natural resiliency of the sturdy bars 50 causes the bars to follow the screws very closely and firmly sets the screws in their base 52.

This mode of supporting drum roll 47 has the added advantage of permitting the-spacing between roll 47 and all three engraved rolls to be set simultaneously. More particularly, the locus of movement of roll 47 on bars 50 is an arc whose center of curvature is located on a line between spacers 51. If the axle 62 of the middle engraved roll 59 is positioned on this arc, then a single adjustment of screws 53 will automatically alter the spacing between the drum roll 47 and each of the engraved rolls 56, 59 and 60 by the same amount. This, of course, assumes that the three engraved rolls are all equally spaced from the surface of drum roll 47 to begin with.

Referring to FIGS. 1 and 2, a set of aluminum doctor blades 64, 65 and 66 are adjustably supported adjacent rolls 5%, 59 and 60 respectively by fixtures 70, 72 and 74 respectively. The doctor blades are urged into engagement with their respective rolls by springs 78, 50 and 82 stretched between the corresponding blades and fixtures. Each doctor blade holds a supply of special printing dye and'knifes it onto the corresponding engraved roll as that rotates. Thus, in the illustrated embodiment, red dye 84, used to print polka dots 116a (FIG. 1), is applied by blade 64 to roll 55; green dye 86, to form dots 16b, is applied by blade 65 to roll 59 and blue dye 88, to form dots 160, is applied by blade 66 to print roll 60. The different color printing dyes are applied by each roll in succession to the raised nap 14a. The dye applied by thevarious rolls dries enough before encountering the next roll so that there is minimum pickoff.

Referring now to FIGS. 2 and 3 of the drawings, the engraved rolls 58, 59 and 60 apply the different portions of the color pattern to nap 14a in exactly the same way. Consequently, for purposes of illustration, we will describe only the operation of the top (i.e. the last) engraved roll 60 as it applies the polka dots 16c.

As mentioned previously, takeup and letoff units 45 and 40 maintain sheet 10 under substantial constant tension to make it uniformly taut across its full width and to prevent the sheet from flapping as it approaches roll 47. Such flapping can alter the spacing between sheet it) and one or more the engraved rolls, causing faulty application of dye. However, these units themselves do not move sheet l0. Rather, drum roll 47 which is driven independently of units 45 and 40 by conventional means (not shown) is the sole means for advancing sheet 10 through printing unit 33. More particularly, sheet 10 engages over a large surface portion of roll 47. Also, it encounters the suction at passages 54 and tends to hug flat against roll 47. In addition, as mentioned previously, the surface 47a of roll 47 is preferably roughened or textured. Consequently, nap 14b and roll surface 47a cooperate to create a relatively high coefficient of friction, large area engagement between sheet 10 and roll surface 47a. All of these factors inhibit relative movement between sheet 10 and roll 47. Therefore, roll 47 can advance sheet Ill at any speed from very slow (or a dead stop) to very fast without any material slippage on roll 47 and despite the fact that sheet 10 is under relatively great tension. These same factors inhibit relative movement between the sheet and print roll 60 which might otherwise tend to cause blurring and displacement of the dots 16c and nap I411.

Preferably, engraved roll 60 (as well as rolls 58 and 59) carry an etchable surface coating (FIG. 3), e.g. copper. A set of recesses 92 is etched in coating 90. The configuration of recesses 92 corresponds to that of the set of polka dots (FIG. 1). Similar sets of recesses are formed in the other rolls 56 and 59 whose arrangements correspond to those of the sets of dots 16a and 16b. Also, the three rolls 58, 59 and 66 are oriented relative to one another at the outset so that their respective recesses 92 are in proper register to print the multiple-color pattern 1611-160 shown in FIG. 1.

As the rolls 47 and 66 rotate, printing dye 65 is knifed onto roll 60. The dye fills recesses 92 in that roll, which then constitute reservoirs of dye which are continuously replenished as the roll rotates.

Referring now to FIGS. 3 and 4, to properly adjust the apparatus, roll 47 is eased up toward roll 60 by careful adjustment of screws 53 (FIG. 2) as described above until flock fibers 14c just extend undisturbed into those recesses 92a in roll 60 which are positioned directly opposite roll 47 (i.e. the recesses 92 which are closest to roll 47). Typically, supporting bars 50 are free to flex about three-fourths inch to permit extremely accurate control over the positioning of these fibers in recesses 92a. On the other hand, those fibers 14d not opposite such recesses 92a are gently pushed aside or deflected by coating 90. Consequently, the upper ends of flock fibers 140 are immersed in dye 88 contained in the opposing recesses 92a, while the remaining fibers 14d which are not to be colored remain untouched by the dye. Thus, substantially no pressure is applied to those flock fibers 140 on which the dots 16c are to be applied. In addition, a slight natural wicking action occurs in the fibers which draws dye 88 in recesses 92 into nap 14a to a typical depth indicated by the dashed line 96 (FIG. 4).

As mentioned above, the surfaces of the drum and print rolls are perfectly uniform and concentric about their respective axes. Also, the semirigid bars 50 provide extremely firm and stable support for the drum roll 47. As a result, the critical spacing relationship between the flock fibers and the print rolls is maintained across the full width of the sheet and along the entire length of the run at all sheet speeds. It should be emphasized at this point also that the slight engagement between the print roll 60 and fibers 14d does not materially affect the speed of sheet 10 through unit 38.

The requirements of the present technique place special demands on the dye 88. More particularly, the dye must be appreciably more viscous (20-25 percent) than those employed in conventional printing and tipping apparatus. At the same time, however, it cant be so viscous that fibers 14 cannot readily penetrate it.

There are two main reasons for this requirement. First, the usual lower viscosity dye tends to bleed out of recesses 92. This did not present much of a problem in prior machines which apply the dye under pressure like a stamp. I-Iere, however, substantially no pressure is used to apply dye 88 to fibers 140. The fibers are merely dipped into recesses 92. It is essential, therefore, that the recesses 92 contain uniform amounts of dye so that fibers 14 will all penetrate the dye to a uniform extent when the spacing between roll 47 and roll 60 is critically adjusted as discussed above. Otherwise, there may be skips or gaps in the pattern applied to nap 14a, or unsightly print-through to sheet 10.

The maintenance of this uniform fiber penetration is also a principal reason for employing the special vacuum roll 4-7. That is, when sheet 10 is made to tightly cling to a large area of roll surface 47a, the random movements of the sheet and its fibers 14 toward or laterally to the opposing recesses 92a on roll 60 are kept to a minimum.

A second reason for using the special dye 88 is to maximize the situp of the polka dots 160 on nap 14a. More particularly, when dye 88 is applied to fibers 140, it wicks only slightly therein to the depth 96 (FIG. 4). Resultantly, the dye remains concentrated at the top of nap 14a producing particularly sharp and distinct colored dots 16c which sit on the top of nap 14a as best seen in FIG. 3. Yet, at the same time, the dots are firmly anchored to fibers 14 so that there is minimum pickoff. This is in sharp contract to the usual dyes which run quickly into the fibers and result in a rather dull diluted dot.

Further, in order to promote even more the situp of the pattern applied to nap 14a, we use water emulsion dyes as opposed to the lacquer dyes commonly employed in conventional printing and tipping machines. Then, immediately following the coloring operation, we are able to subject sheet 10 bearing pattern 12 in dryer 44 to a dry heat of about 300-35 F. This quickly evaporates the water from dye 88, stopping permanently any further wicking into fibers l4 and permanently adhering dots 160 to the top of nap 14a.

Thus, as seen in the foregoing, the amount of dye applied to fibers Me is substantially unaffected by the travel of sheet over roll 47. Also, the deposit of dye 88'is substantially unaffected by the area of flock 16c being printed at any one time (i.e. the extent of correspondence between recesses 92a and flock fibers Me). The result is that substantially the same amount of dye 88 is deposited on each group of fibers 14c over the entire nap 14a. This, in turn, means not only that the blue dots 16c have substantially uniform tone and intensity, but also, that the number of gaps or missing dots in the pattern is appreciably less. Moreover, there is very little likelihood of the dye 88 being applied directly to the sheet 10.

Finally, the fact that very little pressure is applied to the sheet as it proceeds through the coloring unit 38 means that there is little tendency for the sheet 10 to shift relative to the rolls. Furthermore, as noted above, this tendency is reduced even more due to the suction at passages 54 and to the cooperation between the nap 14b and the textured surface 47a of drum roll 47. Consequently, the outline of each dot 16a-16 colored on nap 14a is sharp and distinct. Moreover, the placement of each dot relative to the others in precise and uniform over the entire flocked sheet.

While in the illustrated embodiment of our invention we have shown apparatus capable of coloring in three colors simultaneously, it is apparent that the same principles may be employed to apply more or fewer colors to nap 14a. Also, our coloring technique ofters practically unlimited variations in the color designs applied to the sheet. For illustrative purposes, we have shown a pattern composed of interspersed sets of polka dots. However, the same technique may be employed to apply one color over another and thereby produce graduations in color or even colored FIGS. on the nap 14a.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in carrying out the above method and in the construction set forth without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

We claim:

1. Apparatus for applying a color pattern to the raised nap ofa flocked sheet (10) comprising:

A. an engraved roll (60) having recesses (92) therein;

B. a drum roll (47) spaced parallel to said engraved roll so that the sheet can advance between said rolls;

C. means (48, 63) for rotating said rolls in unison;

D. means (66) for applying dye to said engraved roll so as to fill the recesses therein; and

E. means for critically adjusting the spacing between said rolls so that the flock fibers (14c) on the sheet positioned opposite said engraved roll; 1. just protrude into the opposite recesses therein, and 2. take on dye when under substantially no applied pressure by combined dipping and wicking action, said adjusting means including, a. a pair of stiff, resilient beams (50) supporting the opposite ends ofsaid drum roll, and b. means (53) for bending said beams so as to ease the rolls toward one another. 2. Apparatus as defined in claim I wherein: A. said drum roll;

1. is hollow, and 2. has a multiplicity of passages therein, and

B. further including means (55, 56) for connecting the intenor of said drum roll to a source of pressure below atmospheric so that a vacuum is created at said passages for holding the flocked sheet.

3. Apparatus as defined in claim 2 wherein the surface (470) of said drum roll is textured.

4. Apparatus as defined in claim 2 and further including a plate (57) spaced slightly from the surface portion of said drum roll unengaged by the sheet so as to block selected ones of said passages.

5. Apparatus as defined in claim 1 and further including additional engraved rolls (6], 62) spaced parallel to said drum roll, all of said engraved rolls being arranged with respect to said beams so that adjustment of said beams through a small angle produces substantially equal changes in the spacings between said drum roll and all of said engraved rolls.

6. Apparatus as defined in claim 1 and further including means (54, 56, 47a, 42, 43) for inhibiting relative movement between said drum roll and the flocked sheet engaging around said roll.

7. Apparatus as defined in claim 1 and further including means (43) for increasing the width of the flocked sheet prior to its engagement around said drum roll.

8. Apparatus for applying a color pattern to the raised nap of a flocked sheet (10) comprising:

A. at least one rotary engraved roll (60) having recesses (92) therein for containing a viscous dye during rotation of the rolls;

B. a rotary drum roll (47) spaced parallel to said engraved rolls so that the sheet can advance between said drum roll and said engraved rolls, dye (88) contained in said recesses, said dye being sufficiently viscous to remain in said recesses during rotation of said engraved rolls;-

C. means (48, 63) for rotating said rolls in unison; and D. means (50,53) for adjusting said drum roll toward said engraved rolls so that the flock fibers (14c) on the sheet engaging over said drum roll which are positioned opposite the dye filled recesses in said engraved rolls are dipped into said dye under substantially no pressure, while said fibers not opposite said dye filled recesses are deflected by said engraved rolls, said adjusting means including: a. a pair of stiff, resilient beams supporting the opposite ends of said drum roll, and b. means (53) for bending said beams so as to ease the rolls toward one another.

9. Apparatus as defined in claim 8 when said drum roll is made of aluminum; and has a hard roughened surface (47a) for engaging the flocked sheet.

10. An apparatus as defined in claim 8 wherein said drum rolLis hollow, and contains a multiplicity of passages (54) connecting' the interior of said drum roll and its surface, and means (56) for drawing a vacuum in said drum roll so that the flocked sheet engaging over said drum roll tends to cling thereto.

11. Apparatus as defined in claim 10 and further including means (57) spaced from a surface portion of said drum roll unengaged by the sheet for blocking selected ones of said passages. 

1. Apparatus for applying a color pattern to the raised nap of a flocked sheet (10) comprising: A. an engraved roll (60) having recesses (92) therein; B. a drum roll (47) spaced parallel to said engraved roll so that the sheet can advance between said rolls; C. means (48, 63) for rotating said rolls in unison; D. means (66) for applying dye to said engraved roll so as to fill the recesses therein; and E. means for critically adjusting the spacing between said rolls so that the flock fibers (14c) on the sheet positioned opposite said engraved roll;
 1. just protrude into the opposite recesses therein, and
 2. take on dye when under substantially no applied pressure by combined dipping and wicking action, said adjusting means including, a. a pair of stiff, resilient beams (50) supporting the opposite ends of said drum roll, and b. means (53) for bending said beams so as to ease the rolls toward one another.
 2. take on dye when under substantially no applied pressure by combined dipping and wicking action, said adjusting means including, a. a pair of stiff, resilient beams (50) supporting the opposite ends of said drum roll, and b. means (53) for bending said beams so as to ease the rolls toward one another.
 2. Apparatus as defined in claim 1 wherein: A. said drum roll;
 2. has a multiplicity of passages therein, and B. further including means (55, 56) for connecting the interior of said drum roll to a source of pressure below atmospheric so that a vacuum is created at said passages for holding the flocked sheet.
 3. Apparatus as defined in claim 2 wherein the surface (47a) of said drum roll is textured.
 4. Apparatus as defined in claim 2 and further including a plate (57) spaced slightly from the surface portion of said drum roll unengaged by the sheet so as to block selected ones of said passages.
 5. Apparatus as defined in claim 1 and further including additional engraved rolls (61, 62) spaced parallel to said drum roll, all of said engraved rolls being arranged with respect to said beams so that adjustment of said beams through a small angle produces substantially equal changes in the spacings between said drum roll and all of said engraved rolls.
 6. Apparatus as defined in claim 1 and further including means (54, 56, 47a, 42, 43) for inhibiting relative movement between said drum roll and the flocked sheet engaging around said roll.
 7. Apparatus as defined in claim 1 and further including means (43) for increasing the width of the flocked sheet prior to its engagement around said drum roll.
 8. Apparatus for applying a color pattern to the raised nap of a flocked sheet (10) comprising: A. at least one rotary engraved roll (60) having recesses (92) therein for containing a viscous dye during rotation of the rolls; B. a rotary drum roll (47) spaced parallel to said engraved rolls so that the sheet can advance between said drum roll and said engraved rolls, dye (88) contained in said recesses, said dye being sufficiently viscous to remain in said recesses during rotation of said engraved rolls; C. means (48, 63) for rotating said rolls in unison; and D. means (50,53) for adjusting said drum roll toward said engraved rolls so that the flock fibers (14c) on the sheet engaging over said drum roll which are positioned opposite the dye filled recesses in said engraved rolls are dipped into said dye under substantially no pressure, while said fibers not opposite said dye filled recesses are deflected by said engraved rolls, said adjusting means including: a. a pair of stiff, resilient beams (50) supporting the opposite ends of said drum roll, and b. means (53) for bending said beams so as to ease the rolls toward one another.
 9. Apparatus as defined in claim 8 when said drum roll is made of aluminum; and has a hard roughened surface (47a) for engaging the flocked sheet.
 10. An apparatus as defined in claim 8 wherein said drum roll is hollow, and contains a multiplicity of passages (54) connecting the interior of said drum roll and its surface, and means (56) for drawing a vacuum in said drum roll so that the flocked sheet engaging over said drum roll tends to cling thereto.
 11. Apparatus as defined in claim 10 and further including means (57) spaced from a surface portion of said drum roll unengaged by the sheet for blocking selected ones of said passages. 